ScummVM is a cross-platform interpreter for several point-and-click adventure engines. This includes all SCUMM-based adventures by LucasArts, Simon the Sorcerer 1&2 by AdventureSoft, Beneath a Steel Sky and Broken Sword 1&2 by Revolution, and many more.
ScummVM is a program which allows you to run certain classic graphical point-and-click adventure games, provided you already have their data files. The clever part about this: ScummVM just replaces the executables shipped with the games, allowing you to play them on systems for which they were never designed!